Patent US4822471A successfully refreshed from Google Patents.
Patent US3847519A successfully refreshed from Google Patents.
US3847519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gear pump arrangement
Assignee: Robert Bosch GmbH
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Filing: 1973-06-13
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Granted: 1974-11-12
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Expires: 1993-06-13
Abstract
Abstract The meshing gears of a gear pump are mounted on bearing bodies, and have inlet and outlet regions. Two axially extending strips in the outlet region, crossing the gears and bearing bodies, are subjected to inward fluid pressure and close channels around the gears communicating with the inlet so that inlet and outlet are fluid-tightly separated near the outlet.
Inventors
- 👤 W Dworak
- 👤 W Talmon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:15
CPC Classifications
F; F04; F04C; F04C15/00; F04C15/0003; F04C15/0007; F04C15/0019; F04C2/00; F04C2/08; F04C2/082; F04C2/086
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
209 words
Gear pump arrangement, comprising housing means having an inlet and an outlet for a liquid, and forming a cavity between said inlet and said outlet; two pairs of bearing bodies mounted in said cavity; rotary gear means including a pair of meshing gears between said bearing bodies, and two pairs of shaft portions rotatably supported by said bearing bodies, said gears having opposite inlet and outlet regions communicating with said inlet and outlet; said cavity having an endless inner surface formed with a pair of circumferential channels extending around said gears, respectively, and having first ends communicating with said inlet and second ends located near said outlet region; and two resilient metal strips axially extending across said gears and bearing bodies and having radially inner faces fitting on the outer surfaces of said bearinG bodies and on the outer ends of the teeth of said gears, and radially outer faces forming two pressure chambers with said inner surface, communicating with said outlet so that said strips are pressed inward exclusively by high pressure liquid and cooperate with the ends of the teeth of said gears in said outlet region while closing said second ends of said channels whereby said inlet and said outlet are fluidtightly separated by said strips.
Claim 2
Dependent Claim
209 words
Gear pump arrangement, comprising housing means having an inlet and an outlet for a liquid, and forming a cavity between said inlet and said outlet; two pairs of bearing bodies mounted in said cavity; rotary gear means including a pair of meshing gears between said bearing bodies, and two pairs of shaft portions rotatably supported by said bearing bodies, said gears having opposite inlet and outlet regions communicating with said inlet and outlet; said cavity having an endless inner surface formed with a pair of circumferential channels extending around said gears, respectively, and having first ends communicating with said inlet and second ends located near said outlet region; and two resilient metal strips axially extending across said gears and bearing bodies and having radially inner faces fitting on the outer surfaces of said bearinG bodies and on the outer ends of the teeth of said gears, and radially outer faces forming two pressure chambers with said inner surface, communicating with said outlet so that said strips are pressed inward exclusively by high pressure liquid and cooperate with the ends of the teeth of said gears in said outlet region while closing said second ends of said channels whereby said inlet and said outlet are fluidtightly separated by said strips.
Claim 3
Dependent Claim
57 words
Arrangement as claimed in claim 1, wherein said inner surface of said housing means is formed with two axial grooves extending across said gears, respectively, and at least partly over said bearing bodies and crossing said second ends of said channels; and wherein said strips are located in said grooves, respectively, and form therein said pressure chambers.
Claim 4
Dependent Claim
25 words
Arrangement as claimed in claim 2, wherein said axial grooves and said strips extend over the entire axial length of said bearing bodies and gears.
Claim 5
Dependent Claim
30 words
Arrangement as claimed in claim 1, wherein said teeth of said gears project radially beyond the outer surfaces of said bearing bodies at a distance not more than 0.05 mm.
Claim 6
Dependent Claim
87 words
Arrangement as claimed in claim 1, wherein said endless inner surface is formed by two overlapping cylindrical surfaces; and wherein the outer surfaces of each bearing body includes a cylindrical face portion, and a planar face portion abutting the planar face portion of the respective other bearing body, said cylindrical face portions fitting into said overlapping cylindrical surface portions, respectively, and said strips being transversely curved to fit on said cylindrical face portions of said outer surface and on the ends of the teeth of said gears.
Claim 7
Dependent Claim
15 words
Arrangement as claimed in claim 1, wherein said strips are made of an aluminum alloy.
Claim 8
Dependent Claim
25 words
Arrangement as claimed in claim 1, wherein said strips have abutting axially extending adjacent edges having cutouts forming an outlet opening in said outlet region.
Claim 9
Dependent Claim
29 words
Arrangement as claimed in claim 7, wherein the edges of said strips remote from said abutting adjacent edges cross said second ends of said channels and close the same.
Claim 10
Dependent Claim
23 words
Arrangement as claimed in claim 1, wherein said strips cover peripheral surface portions of said gears, respectively, having not more than three teeth.
Claim 11
Dependent Claim
31 words
Arrangement as claimed in claim 1, wherein the ends of the teeth of said gears are spaced from said inner surface of said housing means in the regions of said channels.
Claim 12
Dependent Claim
36 words
Arrangement as claimed in claim 7, wherein said radially outer faces of said strips are provided with wedged-shaped impressions forming a star-shaped pattern and communicating with said outlet opening to improve the resiliency of said strips.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |